Protective cover for electric switches



NOVo E9, 1936. A BALL PROTECTIVE COVER FOR ELECTRIC SWITCHES Original Filed 001;. 6, 1921 'IIIl/IIIII/I/III/II Patented Nov. 10, 1936 UNITED STATES 2,000,603 rnoTEc'rIvE covEn roa anaemic- SWITC HES Albert P. Ball, Detroit, Mich., Mm; to Square D company, Detroit, Mich., a corporation of Michigan Application October 6, 1921, Serial No. 505,740 Renewed May21, 1931 16 Claims. (01. 200-168) My invention relates'to a switching apparatus and it has special relation to a switch embodying means for protecting the live contacts therein.

More particularly my invention relates to protective caps or covers, which may be positioned over the stationary contacts in a switch and be so provided with apertures that the normal functions of the contact and its associated parts are not interfered with.

19 In pursuance of this object I provide a cap or cover for the stationary contacts of switches which may be quickly attached to, and detached from,

the switch itself.

For a better understanding of my invention ref 1g erence may be had to the accompanying drawing,

in which:

Figure 1 is a fragmentary plan view of a portion of an enclosed switch, the cover of said switch being removed;

1 Fig. 2 is a perspective view of one of my switch contact covers;

Fig. 3 is another perspective view of said cover taken from the diagonally opposite corner; and,

Fig. 4 is an elevational sectional view taken on the line IVIV of Fig. 1.

Referring more particularly to the drawing, a switch embodies a box It having an operating arm Ii pivoted in the walls thereof and adapted to move a plurality of movable-contacts l2, the latter being secured to the operating member II by links it. Positioned within the casing of the switch is a base it of particular form which serves to secure contact mounting blocks I! in position. It will be observed that these blocks have shoulders it against which the base I abuts and holds said blocksin position when said base is secured to the back of the box I9. This novel contactmounting block arrangement is more fully described in my co-pending application, Serial No. 623,356 filed March 7, 1923 and assigned to the Square D Company.

Mounted on an upper portion ll of the block II is a stationary switch contact it which com- 6 prises a clip portion I! to receive the blade l2 and a laterally extending plane portion 20. A solder lug 2| is secured to the top of the portion II and to the right of the clip portion IS, the same being screwed down on to the conducting I. piece 2| whereby a circuit is established from the connector 2| and the clip portion I 9.

My improved protecting member comprises a molded cap 22 (preferably of porcelain, although other insulating material may be used) which may 56 be placed over the stationary contact as shown at the right of Figure 1. This'cap comprises a relatively high portion 23, which is apertured at 24, as shown, to receive the blade l2 as it moves therethrough into contact with the clip portion l9. At the opposite side of the clip I9 is an aper- 5 tured housing 25, which permits of the egress of the line terminal connector 2|, although it substantially surrounds and protects the same. At the base of the cap, and exteriorly thereof, are formed two lugs 26-26, for purposes to be here- 10 inafter described. The top and bottom apertures produce an appreciable air current thru the cap housing which suppresses any incipient arc that may be formed when the contacts are separated. 0

For purposes of illustration I have shown one of the stationary contacts, namely that one to the left in Fig. 1, as unprotectedby a covering, whereas the stationary contact to the right in Fig. I has .one of my novel caps positioned thereover. These caps are very quickly and expeditiously attached to, and detached from, their over-lying position bythe use of spring clips 21, the latter being bowed and provided at each end with a curled engaging portion 28. One of these curled portions fits into a depression 29 in the lug, while the other engages the under side of the plate or base II; a hole 30 being provided in said plate It through which the spring 21 passes. It will be observed that one of these springs is positioned 30 in securing relation on each side of the cover 22.

When these caps are positioned as shown, the movable contacts may pass freely into cooperative relation with the stationary contacts and, in this position of the elements, substantially all of the live metal portions of the movable and stationary contacts are covered. On the other hand, when the movable contacts are movedto switch opening position, the stationary contacts remain substantially protected since the 40 apertures therethrough are so small that it is, impossible for ordinary workmen to come into contact with the live portions of the stationary switch contacts. I find that such protective cov-- ers add greatly to the safety of switches, and at the same time do not interfere at all-with the normal operation of the latter. They also serve to suppress incipient arcs by reason of the air currentwhicli is induced thru them.

While I have described but one embodiment of my invention it is obvious that many modifications thereof may occur to those skilled in the art and I desire, therefore, that the same be limited only by the showing of the prior art and by the scope of the appended claims.

What I now claim as new and desire to obtain by Letters Patent of the United States is:

1. In a switch embodying a fixed contact and a movable contact cooperative therewith, a line wire connected to said fixed contact, protective means for said fixed contact comprising a readilyremovable cap admitting of the entrance of said movable contact and of a line wire, and at the same time protecting all the live parts of said fixed contact when said switch is open.

2. In a switch embodying a fixed contact cooperative therewith, a line wire connected to said fixed contact, protective means for said fixed contact comprising a readily-removable cap apertured to permit the engagement of said movable and fixed contacts and the entrance of a line wire, said cap being so formed that access to said fixed contact is substantially impossible, both when said switch is open and closed.

3. As a new article of manufacture a porcelain switch-contact cover having apertures therein to permit the passage of cooperative contacts and line wires, and having portions thereon which can be utilized in attaching said cap to a switch.

4. As a new article of manufacture a porcelain switch-contact cover having apertures therein to permit the passage of cooperative contacts and having lugs formed at the bottom edge thereof whereby said cap can be secured in position over a contact.

5. As a new article of manufacture a porcelain switch-contact cap comprising a hollow body portion, said cap having a relatively high portion to cover an upstanding contact and a relatively lower portion to cover the binding post of said con tact.

6. As a new article of manufacture a porcelain switch-contact cap comprising a hollow body portion, said cap having a relatively high portion to cover an upstanding contact and a relatively lower portion to cover the binding post of said contact, said high portion having an aperture at the top and side whereby a blade contact can be moved into wiping engagement with the upstanding contact and said low portion being apertured to permit the egress of a binding post member.

7. As a new article of manufacture a porcelain switch-contact cover and having portions thereon which can be utilized in attaching said cap to a switch and having lugs formed at the bottom edge thereof, and a spring having one end cooperating with said lugs.

8. In a switch embodying a fixed contact and a movable contact cooperative therewith, protective means for said fixed contact comprising a cap permitting the entrance of said movable contact and at the same time protecting all the live parts of said fixed contact when said switch is open, and means for quickly attaching and detaching said cap to and from its protective position.

9. In a switch embodying a fixed contact and a movable contact cooperative therewith,,protective means for said fixed contact comprising'a cap permitting the entrance of said movable contact and at the same time protecting all the live parts of said fixed contact when said switch is open, and spring means for quickly attaching and detaching said cap to and from its protective position.

10. In a switch embodying a fixed contact and a movable contact cooperative therewith, protective means for said fixed contact comprising a cap permitting the entrance of said movable contact and at the same time protecting all the live parts of said fixed contact when said switch is open, and independent spring means for quickly attaching and detaching said cap to and from its protective position.

11. In a switch embodying a fixed contact mounted on a base having a hole therein and a movable contact cooperative therewith, protective means for said fixed contact comprising a cap permitting the entrance of said movable contact and at the same time protecting all the live parts of said fixed contact when said switch is open, and spring means, one end of which cooperates with said cap, and the other end of which is positioned in the hole in said base, to secure said cap in protective position.

12. In a switch embodying a fixed contact and a movable contact cooperative therewith, protective means for said fixed contact, and means for quickly attaching and detaching said cap to and from protective position.

13. In a switch embodying a fixed contact and a movable contact cooperative therewith, protective means for said fixed contact, and means comprising a bowed spring for quickly attaching and detaching said cap to and from protective posi tion.

14. In a switch embodying a fixed contact mounted on a base having a hole therein and a movable contact cooperative therewith, protective means for said fixed contact comprising a cap permitting the entrance of said movable contact and at the same time protecting all the live parts of said fixed contact when said switch is open, said cap having lug portions extending parallel to said base, and a bowed spring having coiled ends, one end of which cooperates with a lug portion and the other end of which passes through said hole and engages the=under side of said base, to secure said cap in protective position.

15. In a switch embodying a fixed contact and a movable contact blade, protective cap means adapted to be placed over said fixed contact and to allow said movable contact to be moved through said cap means and into engagement with said fixed contact, the walls of said cap being so formed as to comprehend a slot through which said blade is moved to open position, and the interior of said cap forming a chamber of substantial size, said cap being provided also with an opening through which a line conductor may pass whereby there are opposed openings in said cap.

16. In an electric switch, a base, a contact clip mounted thereon, a pivoted switch blade co-operable with said clip, acne-piece fireproof block having a recess receiving said clip and having at one side of said recess and above the same a relatively narrow longitudinal slot which receives said blade when the latter is closed, and meanssecuring said block against said base and around the inner end of said clip, the outer end of said block being outwardly spaced from the outer end of said clip, the aforesaid slot opening through the longitudinal side of the block toward the blade pivot and the rear wall of said block extending forwardly into the slot at the outer end of said block.

ALBERT P. BALL. 

